Hi Bret, I think the apparent higher symmetry (P212121 vs P21) is due the (pseudo)-twinning operator (a 2-fold axis). So refinement with a twin law (h,-k,-l) will work only in the lower symmetry space group (P21). I hope it helps. Gino ****************************************************************************** Gino Cingolani, Ph.D. Associate Professor Thomas Jefferson University Dept. of Biochemistry & Molecular Biology 233 South 10th Street - Room 826 Philadelphia PA 19107 Office (215) 503 4573 Lab (215) 503 4595 Fax (215) 923 2117 E-mail: [email protected] Website: http://www.cingolanilab.org ****************************************************************************** "Nati non foste per viver come bruti, ma per seguir virtute e canoscenza" ("You were not born to live like brutes, but to follow virtue and knowledge") Dante, The Divine Comedy (Inferno, XXVI, vv. 119-120) ________________________________ From: [email protected] [[email protected]] on behalf of Bret Wallace [[email protected]] Sent: Sunday, March 18, 2012 12:07 PM To: PHENIX user mailing list Subject: Re: [phenixbb] Refinement using data with pseudo translational symmetry Nat, I have been using the auto.ncs function in phenix, but I haven't really looked to see if they are properly defined myself. Pavel, At this point I have not tried using the ordered_solvent command in phenix yet to find waters. I will try that real quick before I bother you to have a look at it. I'll let you know the updated R's afterwards. Gino, It is interesting that you say that, because I after I lowered the symmetry to P21, and re-ran xtriage, it mentioned that I had pseudo-merohedral symmetry, but I didn't pursue that further. My beta-angle was also ~90.2 in this case, and the twinning operator is the same (h, -k, -l). I will detwin and re-refine and see what happens, Thanks everyone and I'll let you know what works, Bret